The nation's major television news networks and the Associated Press filed a federal lawsuit against the state of Minnesota on Monday, arguing that a new law that keeps exit pollsters at least 100 feet away from voting places is unconstitutional and interferes with their right to do their job.

ABC, CBS, CNN, Fox News and the Associated Press insist that the law is too restrictive. The law had earlier prohibited exit polling within 100 feet of where actual voting takes place. But the language was amended in April to read: "No one except an election official or an individual who is waiting to register or to vote shall stand within 100 feet of the building in which a polling place is to be located."

Susan Buckley, an attorney representing the news organizations, said no other state has such a restriction.

The news organizations are asking the court to declare the law unconstitutional and to allow exit polling within the 100-foot zone. Moving pollsters outside the zone, the news organizations argue, could make exit polls less accurate and less helpful to the public.

For instance, polling reporters generally stand near the exit of a voting place and approach voters after they leave. Often they will approach every third voter, or every fourth, to ensure scientifically valid poll results. But if the reporters are pushed too far away from where the voting actually takes place, the news organizations argued in their complaint, the information gathered is less reliable. Voters are more likely to leave the area before they can be approached by reporters or they are more likely to blend in with other people who did not vote, the complaint said.

Nov. 4 is likely to be one of the most closely watched election days in U.S. history, the networks said. For that reason, they must have access to polling places.

The lawsuit names Secretary of State Mark Ritchie and Attorney General Lori Swanson as defendants in the case. Neither could be reached Monday evening for comment.

But state Rep. Bill Hilty, DFL-Finlayson, one of the amendment's authors, said the intent of the law was to clarify the existing 100-foot restriction for election judges.

"They had asked for some clarity on this," he said, adding that it is easier to determine a 100-foot distance from the exit of a building than from the room where voting takes place.

The law, he said, is necessary to ensure voters' rights.

"We have the law in the first place because there has to be some distance between people attempting to vote in private, without someone standing over their shoulder," Hilty said. "I guess my feeling is if it comes down to a question over whether people get to exercise their right to vote in private without being harassed or whether ABC gets to conduct their exit polling where they want, I kind of come down on the side of the voters."

Buckley said this battle has been fought in Minnesota before -- and won by the networks.

A 1988 decision by U.S. District Judge David Doty sided with the networks on an earlier version of the law, which prohibited observers from speaking to anybody about who they voted for, she said.

"He struck that down," she said. Subsequent amendments to the law had not been challenged in court, she said. "But when the new amendment was made, it just became untenable."

Exit polling provides vital data to the public about trends in voter behavior, as well as an accurate way to predict results, the networks said in their complaint.